The present invention relates to an implant syringe needle arrangement which is composed of a syringe needle, a projecting grip member and a preparation receiving member that are interconnected and seated in a guide means to perform a joint axial movement, and further comprising a plunger the advance movement of which towards the syringe needle is limited by an abutment such that a distance which is at least equal to the length of a preparation to be administered remains between the exit opening of the syringe needle and the head end of the plunger, the syringe needle arrangement being retractable by means of the grip member at least by a distance corresponding to the length of the preparation.
Such an implant syringe is used for administering an elongated strand-shaped preparation with a sustained release substance into a patient's body. Most of the time, the sustained release preparation is placed into the patient's abdominal wall into which a receiving channel for the preparation has previously been pierced by means of the syringe needle.
German Patent No. 197 34 385 C1 discloses an implant syringe of the above-mentioned kind. Said implant syringe is handled such that the insertion channel is first formed by piercing the syringe needle, for instance, into a patient's abdominal wall to such an extent that the front edge of a two-part guide sleeve of the implant syringe comes to rest on the patient's skin. After a spacer element has been removed, the plunger is then pushed forwards by a base plate gripping behind a spacer of the implant syringe and by exerting pressure on an end plate connected to the plunger. The plunger pushes the preparation forwards into the syringe needle until a sleeve connected to the plunger impinges on the base plate of the spacer.
Subsequently, the implant syringe is gripped on the front grip member and the base plate of the spacer, and the grip member is retracted up to an abutment. Upon impingement on the abutment the syringe needle is fully retracted from the preparation which is thereby deposited in the insertion channel, whereupon the implant syringe is removed.
With such an implant syringe a preparation, which need not necessarily have an elongated strand-shaped form, can be deposited exactly in the insertion channel, said operation being carried out without any pain—apart from the formation of the insertion channel. A drawback of the known implant syringe is that the syringe needle must be gripped around for retraction of said needle, which renders the handling of the syringe difficult.